Evaluating clinical associations of immediate post-traumatic headache: a prospective multicenter study

Post-traumatic headache (PTH) is a frequent early consequence of head traumatic injury, yet emergency departments (EDs) lack practical tools to identify high-risk patients. Whether routinely documented trauma characteristics are associated with immediate PTH beyond established clinical factors remains uncertain.

This prospective, multicenter observational study evaluated patients aged ≥ 18 years presenting with head and/or neck trauma to the ED between 2022 and 2025. To adhere strictly to ICHD-3 criteria and prevent severity measurement bias, the primary analysis was restricted exclusively to a homogeneous cohort of 495 patients with mild traumatic head injury (GCS 13-15, no traumatic brain CT abnormalities). The primary outcome was immediate PTH occurring directly following the traumatic event. To prevent overfitting, candidate variables were restricted a priori to 9 core features. We utilized multivariable logistic regression and evaluated internal validity via 500 bootstrap resamples.

Immediate PTH occurred in 62.8% of patients with mild head trauma. Prior headache history showed the strongest association with PTH. Several trauma-related characteristics, including posterior, frontal, and temporal impact locations, scalp hematoma, and traffic accident mechanism, were independently associated with higher odds of PTH. Variance Inflation Factor (VIF) confirmed no significant multicollinearity (< 1.85). The parsimonious 9-variable model demonstrated robust discrimination and stability, with an apparent AUC of 0.855 and an optimism-corrected AUC of 0.843.

An association model based on 9 routine ED variables identified several clinical and specific trauma features strongly associated with immediate PTH in mild head trauma patients. These findings highlight important early prognostic factors and maintain statistical stability; however, external validation is required before widespread clinical application.